D.,
I can think of two possibilities here. Either acting out this way is a manipulative tool your child uses to get what she wants, or she's got an underlying behavioral issue that needs to be dealt with.
If this is a sudden change in your child's behavior, talk it over with her pediatrician. A number of children act out behaviourally as a response to a medical issue, and it could be anything from a food allergy to a hormone balance problem. It's never a bad idea to have a sudden alteration in your child's temerament looked over by a doctor.
On the other hand, when your child behaves this way, do you give her what she wants? A lot of times it's really that simple. If she cries and yells and says she hates you, do you give in to make her happy, or to make yourself feel less guilty, or just to end the conflict? From her perspective, if a tactic works, why wouldn't you use it? This is harder, because it focuses on changing your behavior, in order to change hers. I can't really tell you what exactly the problem is, but these are the two possibilities I'd explore first.
Good luck!!